JP2015082921A - Dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high speed and high torque of a dynamo-electric machine by an inexpensive, simple and highly reliable technique.SOLUTION: In a dynamo-electric machine including a stator, a rotor arranged in the rotating shaft direction rotatably for the stator via an air gap, and a primary mechanism rotating coaxially with the rotor, the primary mechanism includes a fixed position rotating pulley arranged immovably in the rotating shaft direction, and a movable position pulley arranged movably in the rotating shaft direction for the fixed position rotating pulley. The movable position pulley moves integrally with the rotor in the axial direction.

Description

  The present invention relates to a rotating electrical machine, and more particularly to an axial gap rotating electrical machine having a variable air gap used as an electric motor or a generator, or a combination of a transmission.

  Rotating electrical machines such as electric motors and generators are more demanding to be lighter, thinner and smaller than the market, and recently, demands for energy saving and higher efficiency are increasing as a countermeasure against global warming. Furthermore, low vibration, low noise, and low cost are also strongly required. Among them, the axial gap type rotating electrical machine having an air gap in the direction of the rotation axis is a flat and thin structure that is advantageous for thinness, and if the rotor is made into a disk shape, the inertia can be reduced, so even for constant speed operation, variable speed It is a rotating electrical machine suitable for operation, and is a form of a rotating electrical machine that has been attracting attention in recent years.

JP2012-130086A

  On the other hand, there is the above-mentioned patent document as related prior art.

  There are a radial gap type and an axial gap type rotary electric machine, but the rotation principle is the same.

  In a conventional general radial gap type rotating electrical machine, a brushless DC motor (hereinafter referred to as BLDCM) using a permanent magnet as a rotor, a synchronous generator, or a rotor without a permanent magnet was used. In the case of a switched reluctance motor (hereinafter abbreviated as SRM), the stator core is formed by laminating a silicon core with a silicon steel plate, and when focusing on low cost and efficiency, a concentrated winding method is mainly used for winding. .

  In the distributed winding method, the coil end portion that does not contribute to torque generation becomes large, resulting in increased copper loss and reduced efficiency. In the concentrated winding method, the winding is simple and can be directly wound in the slot, so that the winding is inexpensive. Because.

  On the other hand, axial gap type BLDCM and SRM have recently been studied as driving vehicle motors for hybrid vehicles and electric vehicles. The reason is that a flat shape is convenient when it is provided with an engine or an in-wheel motor. In that case, it is known that, particularly in an axial BLDC motor, strong field control is performed so as to obtain a high torque during start-up and low-speed rotation, and weak field control is performed so as to obtain high-speed rotation during high-speed rotation. The reason why such field control is performed is that if the field flux is large, a large torque can be obtained at low speeds, but if the field flux is large at high speeds, the electromotive force constant also increases and the power supply voltage is This is because when the induced voltage approaches, the current stops flowing and the torque decreases. In order to avoid this, it is conceivable to control the field with a multi-pole permanent magnet field motor, but to control the field with a multi-pole permanent magnet field motor, the vector control technology is used and the control is complicated and expensive. Become. On the other hand, in an axial gap type BLDC motor or the like, if the rotor is moved in the axial direction, the air gap between the stator and the rotor is reduced during low-speed rotation, and the distance is increased during high-speed rotation. It is known that the magnetic flux becomes the same characteristic as when the magnetic flux is strengthened or weakened.

  Further, when an axial gap motor is used for powering an electric vehicle (hereinafter abbreviated as EV), a large load torque at the time of starting is required in response to only field control. In direct drive, the motor size is large, and there is a problem in terms of economy and weight, and it is necessary to drive a load via a speed reducer. As the speed reducer, a continuously variable transmission mechanism (hereinafter abbreviated as CVT) that combines a V-belt and a taper pulley is widely used.

  FIG. 14 is a cross-sectional view in which a continuously variable transmission mechanism, so-called CVT, is attached to a typical prior art axial gap type BLDCM. The stator core 19 is generally formed by a silicon steel sheet laminating method. For example, six stator cores 19 are provided with three-phase windings 2, and the rotor has a four-pole example. In addition, illustration of Hall elements etc. is omitted. The rotor includes a permanent magnet 18. The permanent magnet 18 has four fan-shaped segment magnets magnetized in the axial direction, alternately arranged in the circumferential direction with different polarities, and through the air gap in the axial direction. It arrange | positions so that the stator core 19 may be planarly opposed. That is, the conventional axial gap type BLDCM shown in FIG. 14 is a plain air gap type. The rotor includes a back yoke 17, and a magnetic circuit is formed by the back yoke 17. The rotor includes a rotation shaft 7, and the rotation shaft 7 is a shaft body having a tapered surface with a tapered tip. The rotation shaft 7 is fixed in the thrust direction and is rotatable with respect to the stator core 19 through a bearing 11. Is held in. Thus, the back yoke 17 and the permanent magnet 18 are integrally formed to form a rotor. The above is a drive part, ie, a motor.

  The rotor further includes a pulley 8. The pulley 8 is movable in the thrust direction and is rotatably arranged with the rotary shaft 7, and has a tapered so-called inclined surface formed corresponding to the tapered surface of the rotary shaft 7. V-shaped grooves are formed on the tapered surfaces of the rotating shaft 7 and the pulley 8 facing each other, and the V-shaped belt 15 is sandwiched between the grooves. Normally, the pulley 8 is controlled so as to pressurize the V-shaped belt 15 by hydraulic pressure, spring pressure or the like, although not shown. The above is the driving side, and for convenience of explanation, these are called the primary side. When a three-phase alternating current is passed through the winding 2, a rotating magnetic field is generated in the motor, and the V-shaped belt 15 is driven. The V-shaped belt 15 drives the load shaft 20. The load shaft 20 is a shaft body having a shape similar to that of the rotary shaft 7 and having a tapered surface at the tip. The pulley 21 provided rotatably on the load shaft 20 has the same shape as the pulley 8, and has a tapered surface that is movable in the thrust direction and rotatably provided with the load shaft 20. . Similarly to the primary side described above, the V-shaped belt 15 described above is sandwiched between the taper surfaces of the load shaft 20 and the pulley 21. The pulley 21 always pressurizes the V-shaped belt 15 by the spring spring 23 with the stopper 22 fixed to the load shaft 20 as a power point. A load is connected to the right end of the load shaft 20. These are called secondary sides for convenience of explanation. For example, in the case of EV, the primary side is a motor and the secondary side is a drive wheel tire. In such a configuration, a continuously variable transmission mechanism is formed. That is, since the tension of the V-shaped belt 15 increases when the motor starts, the pulley 8 moves to the right side in FIG. 14 and the diameter of the primary side of the V-shaped belt 15 decreases. Since the V-shaped belt 15 bends on the next side, the pressure of the spring spring 23 causes the pulley 21 to slip into the inner periphery of the V-shaped belt 15 and the belt diameter increases. That is, a reduction gear is formed, and a large load torque can be driven. That is, the state is opposite to that in FIG. On the contrary, since the load torque is reduced at the time of high rotation, the tension of the V-shaped belt 15 is loosened on the driving side, or the pulley 8 is controlled by controlling the hydraulic pressure or the spring pressure applied to the pulley 8 described above. However, the V-shaped belt 15 has a speed increasing function because it has a large diameter on the drive side and a small diameter on the load side. That is, the state shown in FIG. 14 is obtained. In this way, continuously variable transmission is possible.

  However, in particular, when speed control is required over a wide range from low speed to high speed, such as in EV applications, CVT alone is not sufficient to perform speed control sufficiently efficiently. Weak field control at high speed and strong field control at low speed Was necessary. In order to perform the weak and strong field control, extra electric power for field control and complicated vector control are required. However, it is known that axial gap motors can achieve the same effects as field-weakening control at high speed and field-intensity control at low speed by making the air gap length between the rotor and stator variable. Yes.

  Japanese Patent Application Laid-Open No. 2012-130086 described above is a prior art in which the gap length is forcibly changed by an external force in the typical axial gap type BLDC motor. However, the method described in the above prior art including the above FIG. 10 and FIG. 11 has the following drawbacks. That is, in the plain air gap type in which the field magnet and the stator iron core are opposed to each other in a plane, the minimum air gap cannot be reduced compared to the radial gap motor. In other words, the axial gap type, in contrast to the radial gap type, has a problem that the air gap length needs to be approximately doubled in consideration of the rotor surface runout, and the torque decreases accordingly. Further, there is a problem that the controllability is not good because the air gap length vs. torque characteristic is not linearly changed with respect to the air gap length but becomes nonlinear.

  Therefore, the present invention has been made in view of the above problems, and by adopting a three-dimensional air gap motor that is a motor structure suitable for the above-described CVT, the position of the air gap variable rotor and the CVT can be varied by an axial gap type. A compact axial variable gap motor having a CVT in which a pulley and a motor are combined with a CVT is provided. The present invention solves the above problems and provides an inexpensive and high-performance axial motor.

  A rotating electrical machine according to the present invention includes a stator, a rotor arranged to be rotatable with respect to the stator through an air gap in a rotation axis direction, and a shaft 1 coaxially rotating with the rotor axis. In a rotating electrical machine having a secondary side mechanism, the primary side mechanism is movable along the rotational axis direction with respect to the fixed position rotary pulley arranged so as not to move in the rotary axis direction and the fixed position rotary pulley. The variable position pulley is configured to rotate integrally with the rotor and move in the axial direction.

  Further, in the rotating electrical machine according to the present invention, the variable position pulley has a conical internal space portion between the rotor and the rotor, and the conical internal portion provided so as not to move in the axial direction within the space portion. And a weight divided into one or a plurality in the circumferential direction of the rotating shaft in a space formed by a plate having an inclined surface in the opposite direction, and the weight is an elastic member that urges in the reduced diameter direction as necessary Is preferably assembled in series.

  Moreover, the rotary electric machine which concerns on this invention WHEREIN: The said rotor can be provided with the permanent magnet magnetized by the different polarity in the circumferential direction by the even number pole.

  In the rotating electrical machine according to the present invention, the rotor may not include a permanent magnet.

  Further, in the rotating electrical machine according to the present invention, the stator has a plurality of winding salient cores having a concentric arc shape and protruding first teeth in the axial direction, and the winding shaft is the rotating shaft. A stator core portion in which a plurality of the winding salient pole cores formed in parallel with each other are arranged in the circumferential direction, and the rotor has a plurality of magnetic poles distributed in the circumferential direction. It is preferable that the rotor magnetic pole has a concentric circular shape and protrudes a second tooth portion disposed so as to face the first tooth portion via the air gap in the axial direction.

  Further, in the rotating electrical machine according to the present invention, a continuously variable transmission mechanism is formed by forming a variable width V-groove with the fixed position and variable position pulleys of the primary side mechanism and the secondary side mechanism, and spanning a V-shaped belt. can do.

  Further, in the rotating electrical machine according to the present invention, electric power is input to the one having the winding of either the stator or the rotor to rotate the primary side mechanism to obtain an output from the secondary side mechanism. be able to.

  In the rotating electrical machine according to the present invention, a driving force can be input to the secondary side mechanism by an external force such as wind power, hydraulic power, or an engine, and the rotating electrical machine provided in the primary side mechanism can be used as a generator.

  If the means for moving the rotor of the axial variable gap type rotating electrical machine according to the present invention in the axial direction and the variable position pulley of the CVT are directly connected, both of them can move in the same way, with high torque at low speed and high speed at high speed. The output characteristics are synergistic with the motor and CVT.

Further, the axial gap type BLDCM according to the present invention can mesh and rotate the first tooth portion formed on the stator and the second tooth portion formed on the rotor so that the interlinkage magnetic flux is twice the plane gap. As a result, the torque at the time of starting and at a low speed can be more than doubled. Compared with the conventional axial gap motor, this motor has low noise because the concave-convex engagement portion also has a radial gap.
Further, since the air gap facing portion between the first tooth portion formed on the stator and the second tooth portion formed on the rotor is in meshing opposition, the facing area increases and the air gap portion permeance is large and highly efficient. In the rotating electrical machine, the axial suction force and torque are almost proportional to the air gap length as the air gap increases, so that torque control can be easily performed by gap length control.

  In addition, since the axial gap type SRM according to the present invention can rotate by meshing the first tooth portion formed on the stator with the concave and convex portions and the second tooth portion formed on the rotor, it can be rotated compared to the prior art. It will be excellent.

  Furthermore, if the axial gap type rotating electrical machine according to the present invention is applied to a driving main machine of an electric vehicle, the power required for a strong field at a low speed and a weak field at a high speed is unnecessary and the efficiency can be increased.

  Also, if the axial gap type rotating electrical machine according to the present invention is configured so that the secondary side shaft of the CVT is driven by wind force, the speed is increased during light winds and is decelerated during heavy winds so that a substantially constant power is obtained. The resulting power generator can be configured.

1 is an axial sectional view of a rotating electric machine according to a first embodiment of the present invention. AA sectional view in FIG. BB sectional view in FIG. Sectional drawing of the axial direction of the rotary electric machine of the modification of the 1st Embodiment of this invention Sectional drawing of the axial direction of the rotary electric machine of the further modification of the 1st Embodiment of this invention Partial sectional view of the weight in FIGS. 4 (a) and 4 (b) Operation explanatory diagram of the rotating electrical machine according to the present invention Operation explanatory diagram of the rotating electrical machine according to the present invention Operation | movement explanatory drawing of the rotary electric machine which concerns on the 2nd Embodiment of this invention. Operation | movement explanatory drawing of the rotary electric machine which concerns on the 2nd Embodiment of this invention. Still another operation explanatory diagram of the rotating electric machine with CVT of the present invention. Operation explanatory diagram of the rotating electrical machine of the present invention Characteristic explanatory diagram of the rotating electrical machine of the present invention Characteristic explanatory diagram of the rotating electrical machine of the present invention Operation explanatory diagram of conventional rotating electrical machine

  This will be described below with reference to the drawings.

[First embodiment]
The stator core 1, the rotor magnetic pole 4, the back yoke 6 of the permanent magnet 5, and the like of the axial gap motor of the present invention can be easily and inexpensively manufactured by pressing soft magnetic iron powder. In the case of the laminated type of silicon steel plates, in the case of the conventional radial gap type, a two-dimensional iron core is laminated in the axial direction, and the field magnetic flux is also used in a plane magnetic path perpendicular to the axis. However, in the axial gap motor, the field magnetic flux magnetic path is three-dimensional, so there is a problem that the magnetic flux cannot pass in the stacking direction in the stacking method to adopt the silicon steel sheet stacking method. However, this was another reason why it was not widespread compared to the radial gap. In this respect, since the dust core is non-directional, it is suitable for forming a three-dimensional shape. The dust core is a soft magnetic iron powder coated with resin, heat treated after pressurization, and can be manufactured in a complicated shape with a press die. Further, the magnetic permeability is inferior to the rolling direction of the silicon steel sheet, but the magnetic flux passing direction is non-directional. Furthermore, since the iron powder is individually insulated with resin, eddy currents are not generated, and an iron core with a small iron loss can be obtained.

  FIG. 1 shows a part of the configuration of the present invention, and shows a shaft rotation type axially variable single gap type rotating electrical machine and a primary part of a CVT. 2 is an AA cross-sectional arrow view of the rotary electric machine of FIG. 1, and FIG. 3 is a BB cross-sectional arrow view of the rotary electric machine of FIG. A first example of the present invention will be described with reference to FIGS.

  As shown in FIG. 2, the stator core 1 has winding salient cores 1b made of a dust core or the like arranged in a disc shape, and the winding salient core 1b is formed as shown in FIG. A plurality of first tooth portions 1a project concentrically in the axial direction and are formed in an arc shape. In the case of this figure, the stator iron core 1 is composed of six substantially fan-shaped winding cores 1b for winding salient poles or six divided iron cores, and the three-phase winding and rotor are examples of four poles. For example, a number of combinations such as 12 slots for the stator and 8, 10, 14 poles for the rotor, or 9 slots for the stator and 8, 10 poles for the rotor can be applied.

  The winding 2 is wound around the outer peripheral surface of the stator core 1, and in this case, six windings are arranged in the circumferential direction as shown in FIG. Six grooves are provided in a substantially fan shape. As shown in FIG. 3, the rotor has four rotor magnetic poles 4 and magnetized permanent magnets 5 on the back side thereof, and four poles are alternately arranged with N and S poles.

  In the permanent magnet 5, it is desirable that four magnet pieces are magnetized so as to have different polarities alternately in the axial direction in the axial direction, and the back yoke 6 is disposed on the back surface thereof. Alternatively, the four rotor magnetic poles 4 may be fixed while being magnetized alternately with S poles and stacked in the axial direction. On the back side of the permanent magnet 5, there is a back yoke 6 or a rotor support, which is fixed to the primary side tacking rotary shaft portion of the fixed position rotary pulley 7. The stator core 1 and the rotor magnetic pole 4 have a first tooth portion 1a and a second tooth portion 4a concentrically protruding in the axial direction, and the stator and the rotor have an air gap in an uneven shape. The bearings 11 and the sliding bearings 10 are opposed to each other so as to be freely rotatable. If this uneven gap is applied to a radial gap type rotating electrical machine, the stator core 1 cannot be assembled unless the stator core 1 is divided and combined with the rotor. However, if it is an axial gap type, assembly is easy. Further, even if the stator and the rotor have the first tooth portion 1a and the second tooth portion 4a that are engaged with each other, the powder iron core manufacturing method can be made easily and inexpensively. A pair of bearings 11 are arranged, and spacers 3 and 9 are interposed between the bearings 11 and on the rotation shaft of the fixed position rotating pulley 7. That is, in FIG. 1, the rotor magnetic pole 4, the permanent magnet 5, the back yoke 6, and the variable position pulley 8 are fixedly combined with each other to form a single rotor. Rotation and thrust movement are possible with the fixed-position rotating pulley 7 having a side-shafted rotating shaft. Since the fixed position rotating pulley 7 is rotatably held by the bearing 11, it is fixed at a fixed position in the thrust direction with respect to the stator. In addition, illustration of Hall elements etc. is omitted.

  Next, the operation of FIG. 1 will be described. When the rotating electrical machine starts the load, a maximum current corresponding to the starting load torque flows from the characteristics of BLDCM. Since the axial gap motor generates a large suction force in the axial direction as compared with the radial gap motor and is in proportion to the current, the rotor is attracted to the stator core 1 with a minimum predetermined air gap as shown in FIG. Start. Further, since the variable position pulley 8 of the rotor has a large tension of the V-shaped belt 15 at the time of starting, the rotor magnetic pole 4 receives a force in such a direction that the air gap with the stator core 1 is further reduced by the tension. Start. That is, the engine is started with the V-groove interval between the fixed position rotating pulley 7 and the variable position pulley 8 opened. At this time, the diameter of the V-shaped belt 15 is a minimum and a ratio for decelerating the secondary shaft on the load side.

  Next, when the motor speed is increased by duty control, applied voltage control, etc., a large torque is generated due to the small air gap in the rotating electrical machine, and a torque increase due to the deceleration ratio of the CVT is added to this, thereby synergistically loading the load. Easy to start acceleration. Then, when the acceleration is finished and the constant speed operation or the high speed operation is performed, the load is greatly reduced compared to the acceleration time, so that the tension of the V-shaped belt 15 is also reduced. Also, from the relationship between the speed-torque characteristics of BLDCM, as the speed increases, the load current decreases, so the attractive force between the gaps also decreases. At this time, if a biasing means such as a coil spring pressure or hydraulic pressure is provided in this place instead of the spacer 9 for holding the rotating shaft of the fixed position rotating pulley 7, the taper portion of the variable position pulley 8 becomes a V-shaped belt. The diameter of the V-shaped belt 15 is increased while rotating around the inner periphery of the belt 15. As the diameter of the V-shaped belt 15 is increased, the air gap between the stator and the rotor is expanded, a field weakening effect is generated and the rotational speed is increased, and a speed increasing ratio is also achieved on the CVT side, thereby producing a synergistic effect. . 1, the generated torque is transmitted to the fixed-position rotating pulley 7 through the frictional force of the V-shaped belt 15. Further, it is important that the gap length and the generated torque change linearly, but this can be solved by applying an example described in FIGS. 11 and 12 described later.

  FIG. 1 shows an example in which the air gap of the rotating electrical machine is increased or decreased by a change in current at the speed of the rotating electrical machine, a spring pressure, or a hydraulic pressure, while FIG. In FIG. 4A, the motor part is substantially the same as in FIG. The CVT portion is different from FIG. 1 and the variable position pulley 8 in FIG. 1 is a solid conical member. However, in FIG. 4A, a hollow cone 30 is provided and the back yoke (rotor support) is provided with the hollow cone 30. A plate 12 having an inclined surface opposite to the inner wall surface of the hollow cone 30 fixed on the outer periphery and having a space surrounded by the back yoke 6 and the hollow cone 30 and fixed in the thrust direction is provided. The central portion of the hollow cone 30 is capable of rotating and thrusting via a sliding bearing (not shown) with respect to the fixed position rotating pulley 7. A weight 13 obtained by dividing one piece or a donut-like body into a plurality of parts is disposed in the interior, that is, in the space portion formed by the plate 12 and the inner wall of the hollow cone 30. The weight 13 has an elastic member 14 that urges the weight 13 in the diameter-reducing direction as necessary in the center hole portion thereof, and is arranged around a primary shaft that is a fixed-position rotating pulley 7. The elastic member 14 is, for example, an elastic string, an annular spring, or an elastic ring body. A V-shaped belt 15 is provided in a V-groove formed by the hollow cone 30, the fixed-position rotating pulley 7, and the inclined surface. Note that the shape of the weight 13 is not limited to a donut-like body, and can be appropriately applied, such as connecting a spherical weight with an elastic member 14.

  The operation will be described below.

  When the rotating electrical machine starts the load, a maximum current corresponding to the starting load torque flows from the characteristics of BLDCM. The axial gap motor generates a large axial attractive force as compared to the radial gap motor, and the attractive force is proportional to the current. Therefore, as shown in FIG. Aspiration starts at the air gap. Further, the rotor cone 30 loses the tension because the tension of the V-shaped belt 15 is large at the start, and the rotor magnetic pole 4 receives a force in the direction in which the air gap with the stator core 1 is further reduced. That is, the engine is started in a state where the gap between the V-grooves between the fixed position rotating pulley 7 and the hollow cone 30 is open. At this time, the diameter of the V-shaped belt 15 is a minimum and a ratio for decelerating the two axes on the load side.

  Next, when the motor speed is increased by duty control, applied voltage control, etc., the rotating electrical machine can increase the torque due to the CVT deceleration ratio in addition to the large torque due to the small air gap, making it easy to start and accelerate the load with a synergistic effect. This state is shown in the upper half of the horizontal axis of FIG. 4A. Then, the acceleration is finished, and in the constant speed operation or the high speed operation, the load is greatly reduced as compared with the acceleration time. Further, because of the relationship between the speed-torque characteristics of BLDCM, the load current decreases as the speed increases, so that the gap attractive force also decreases.

  At this time, as the speed of the weight 13 increases, a centrifugal force is generated and the force is received in the radial direction of the rotating shaft, and the lower half of FIG. That is, the weight 13 pushes the cavity cone 30 and the inner wall of the plate 12 outward by centrifugal force, but the plate 12 is fixed in the thrust direction to the rotation axis of the fixed position rotating pulley 7, so the cavity cone 30. 4A moves to the right in FIG. 4A, pushes up the position of the V-shaped belt 15 in the outer peripheral direction, increases the diameter of the V-shaped belt 15, and increases the speed ratio. At the same time, the rotor magnetic pole 4, the permanent magnet 5, and the back yoke 6 as the rotor are also moved to the right by the same amount to widen the air gap between the stator core 1 and the rotor magnetic pole 4 and have a field weakening effect. It is gradually transformed into a high-speed motor. When the weight 13 is at the outer peripheral position due to centrifugal force, the elastic member 14 is extended. When the speed is reduced again, the centrifugal force is lost in the weight 13 when the rotational speed is reduced, so that the force pushing the hollow cone 30 to the right side disappears, and at the same time, tension is applied to the V-shaped belt 15 from the load side. Therefore, the cavity cone 30 is moved to the left side by the tension of the V-shaped belt 15, and the rotor magnetic pole 4, the permanent magnet 5 and the back yoke 6 as the rotor are also moved to the left at the same time, and the air gap is also reduced. The elastic member 14 shrinks and returns to the state shown in the upper half of FIG. FIG. 5 shows a state in which the elastic member 14 is contracted and positioned around the rotation axis of the fixed position rotation pulley 7.

  FIG. 4 (b) opens and closes the air gap by centrifugal force as in FIG. 4 (a). The configuration of the stator and the rotor in FIG. 4B is the same as that in FIG. The rotor secures the first plate 26 on the outer periphery of the back yoke 25. The first plate 26 has a hollow conical shape toward the shaft center, and is not in contact with the shaft 50 fixed to the stator, or can rotate and move in the axial direction with respect to the shaft 50 via the sliding bearing 10. It can move together with the child. A space surrounded by the first plate 26 and the shaft 50 is provided with a second plate 27 having a slope opposite to the inner wall surface of the first plate 26 fixed in the thrust direction. A weight 13 in which one or a donut-shaped body is divided into a plurality of parts is disposed in the inside, that is, in the space formed by the inner walls of the second plate 27 and the first plate 26. The weight 13 has an elastic member 14 that urges the weight 13 in the diameter-reducing direction, if necessary, in the center hole portion, and is disposed around the shaft 50. The weight 13 obtained by dividing the donut-shaped body into a plurality may be a plurality of spheres, and the shape thereof is not limited to this. Although one sphere may be used, a plurality of spheres are preferable because the centrifugal force acts equally on the first plate 26 and the second plate 27. The first plate 26 in FIG. 4B corresponds to the hollow cone 30 in FIG. 4A or the variable position pulley 8 in FIG. 1 and has a similar variable gap function, but the output of the motor is Unlike the transmission to the secondary mechanism by the V-shaped belt 15, the primary mechanism to be transmitted to the rotating body 28 is configured. Note that the shape of the weight 13 is not limited to a donut-like body, and can be appropriately applied, such as connecting a spherical weight with an elastic member 14.

The operation is as follows.
When the rotating electrical machine starts the load, a maximum current corresponding to the starting load torque flows from characteristics such as BLDCM. The axial gap motor generates a large suction force in the axial direction as compared with the radial gap motor, and the suction force is proportional to the current. Therefore, as shown in the upper half of the axis of the shaft 50 in FIG. The rotor is sucked into the stator core 1 with a minimum predetermined air gap and starts to start.

Next, when the motor speed is increased by duty control, applied voltage control, or the like, the internal induction voltage increases and the current decreases, so the thrust attracting force acting between the stator and the rotor also decreases.
At this time, as the speed of the weight 13 increases, a centrifugal force is generated and receives the centrifugal force in the radial direction of the rotating shaft, and the lower half of FIG. That is, the weight 13 pushes up the inner walls of the first plate 26 and the second plate 27 outwardly by centrifugal force, but the second plate 27 is fixed to the fixed shaft 50 in the axial direction. Only the plate 26 moves to the right, and the rotor also moves at the same time, thereby expanding the air gap. In the mode for reducing the speed again, the centrifugal force disappears in the weight 13 when the rotational speed is reduced, so that the force pushing the first plate 26 to the right side disappears, and the current also increases during the low speed rotation, so the axial gap is increased. The air gap is reduced to the minimum position by the unique strong thrust suction force. In FIG. 4B, an external gear is formed on the outer periphery of the rotor or the first plate 26, and an internal gear extending in the axial direction meshes with the inner periphery of the rotating body 28 rotating at a fixed position in the axial direction. Even if the rotor moves in the axial direction, the gears can always mesh and transmit the rotational force to the rotating body 28. When used for driving an in-wheel electric vehicle, a tire may be attached to the outer periphery of the rotating body 28. The following description is the same as FIG.

  6 and 7 are diagrams illustrating the primary side and the secondary side of the CVT at the same time. The motor part is different from FIG. 1 and FIG. 4, but the air gap between the stator and the rotor is not meshed unevenly, but the axial rotor and the CVT variable position pulley 8 are united and moved in the thrust direction at the same time. There are merits that can be done. The rotor includes a stator 19, a permanent magnet 18, and a back yoke 17. Since other members are the same as those in FIG. 1, the same reference numerals as those in FIG. In FIG. 6, when the rotating electric machine starts, the tension of the V-shaped belt 15 increases, so that the variable position pulley 8 is moved to the right side, and the air gap between the permanent magnet 18 and the stator 19 is minimized. In this state, since the VVT between the pulleys of the primary shaft of the CVT is open with a large starting torque, the diameter of the V-shaped belt 15 is small, and it is easy to start with a deceleration ratio.

  If the collar part of the rotary shaft 20 with the secondary side tack of the CVT has a tapered shape and the pulley 21 rotates about the shaft part of the rotation shaft 20 as a central axis and the position movement in the thrust direction is fixed, the V-shaped belt 15 is pressed by a spring 23 and sandwiched between the tapered portion of the rotating shaft 20. The spring 23 is held by a spring stopper 22 attached to the rotary shaft 20. Since the distance between the primary shaft and the secondary shaft of the CVT is constant, if the V groove between the pulleys is opened on the primary side, the belt bends on the secondary side. Recessed into the inner peripheral portion of the V-shaped belt 15 is in a state suitable for starting acceleration in the state shown in FIG.

  FIG. 7 shows a state suitable for a light load at a constant speed or high-speed rotation. After the acceleration, the load is greatly reduced in the constant speed operation or the high speed operation, and the tension of the V-shaped belt 15 is also reduced. Further, because of the relationship between the speed-torque characteristics of BLDCM, the load current decreases as the speed increases, so that the gap attractive force also decreases. Then, the variable position pulley 8 is pulled into the V-shaped belt 15 by pressurization of the spring 16 or the like. At the same time, the tension of the V-shaped belt 15 is applied to the secondary side, and the pulley 21 is fixed at a fixed position in the thrust direction, so the tapered portion of the rotating shaft 20 moves to the left by the tension of the V-shaped belt 15. As a result, the V-groove interval is opened, and the state becomes suitable for high-speed rotation in the figure.

  In addition, when a windmill or the like is attached to the secondary shaft of the CVT in FIGS. 6 and 7, the rotating electrical machine attached to the CVT primary side can be used as a generator. Since FIG. 6 corresponds to the time of light wind and the secondary side shaft rotates at a low speed, the power generation amount can be increased by increasing the number of revolutions by increasing the speed of the generator on the primary side shaft. Further, FIG. 7 corresponds to a strong wind, and the secondary side shaft rotates at a high speed. Therefore, the primary side shaft rotation can be decelerated to suppress the amount of power generation or to prevent damage due to the high speed rotation of the generator.

[Second Embodiment]
FIGS. 8 and 9 are diagrams for explaining the rotating electrical machine according to the second embodiment by simultaneously showing the primary side and the secondary side of the CVT. As in FIGS. 1 and 4, the motor part has an air gap between the stator core 24 and the rotor magnetic pole 25 meshed in a concave-convex shape, but the number of teeth with which the concave-convex meshes is shown to be small for simplicity It is. It is the same that the axial rotor and the variable position pulley of the CVT have the merit of being able to move together in the thrust direction at the same time. The rotor magnetic pole 25 is an example in which the permanent magnet 18 is attached, the variable position pulley 8 is made of a magnetic material, and the back yoke is used instead. The other members are the same as those in FIG.

  8 and 9 are the same as those in FIG. 6 and FIG. 7, and the explanation of the operation is omitted. However, in FIG. 8, the air gap of the rotating electrical machine is the smallest and the V groove of the CVT is the largest. The figure shows the figure at the time of start-up or acceleration, with the diameter of the letter-shaped belt being the smallest, and hence the diameter of the V-shaped belt on the CVT secondary side being the largest. In contrast, FIG. 9 shows that the air gap of the rotating electrical machine is the largest, the V groove of the CVT is the smallest, the V-shaped belt diameter on the primary side is the largest, and therefore the V-shaped belt diameter on the CVT secondary side is the smallest. It is a figure of time.

  8 and 9, when a windmill or the like is attached to the two shafts of the CVT, the rotating electrical machine attached to the CVT primary shaft can be used as a generator. Since FIG. 8 corresponds to the time of light wind and the secondary side shaft rotates at a low speed, the power generation amount can be increased by increasing the number of revolutions by increasing the speed of the generator on the primary side shaft. Further, FIG. 9 corresponds to a strong wind and the secondary shaft rotates at high speed, so that the primary shaft rotation can be decelerated to suppress the amount of power generation or prevent the generator from being damaged by the high speed rotation. In addition, when applying the rotary electric machine described in FIG.4 (b), a windmill etc. can be directly attached to the rotary body 28, without providing a secondary side axis | shaft, and it can also be used as a generator.

  FIG. 10 shows an uneven air gap having a first tooth portion and a second tooth portion as in the case of FIGS. 8 and 9, wherein the stator core 24 and the rotor magnetic pole 25 of the motor are the same as those in FIGS. FIG. 10 is a diagram when the permanent magnet 18 is not used as in the BLDCM of FIG. 9. This is a so-called reluctance type rotating electrical machine, which is a rotating electrical machine that has been attracting attention as an SRM in recent years. The stator and rotor of the air gap facing portion viewed from the axial direction are the same as those shown in FIGS. This machine rotates with suction force, but the smaller the air gap and the larger the area facing the air gap, the greater the generated torque. In addition, since there is no permanent magnet as compared with BLDCM, the cost is low, but the generated torque is small, so an uneven gap type is required for EV applications and the like. And although not as remarkable as BLDCM, the larger the air gap, the faster the rotation. Therefore, it is effective to apply the CVT device of the present invention to the axial gap type SRM. FIG. 10 is a diagram corresponding to high-speed rotation with a large air gap.

The torque of the rotating electrical machine is proportional to the flux linkage. The flux linkage is proportional to the gap permeance P, and P is given by the following equation.
P = μ ₀ S / L (1)
Here, μ ₀ : vacuum permeability, S: gap facing area, L: air gap length However, since the air gap of the motor in FIGS. The facing area S can easily be two to three times that of the conventional type. Therefore, the permeance P can be increased by 2 to 3 times and the torque can be increased in proportion to P. Therefore, compared with the radial gap type motor, the small torque due to the large air gap, which was a drawback of the axial gap type motor, is improved. As described above, when an uneven air gap is applied to a radial gap motor, the stator and rotor cannot be easily assembled, but an axial gap motor is simple. Although the present invention uses a dust core, the poor magnetic permeability compared with the dust silicon steel plate is also covered by this uneven gap effect. Here, the features of the concave-convex gap type axial gap motor will be described with respect to the so-called plain gap type axial motor in which the stator and the rotor face each other in a plane.

  When the characteristics with the torque T when the gap length L is changed are compared, the characteristics are as shown in FIGS. FIGS. 11A and 11B show a plane gap type, in which a permanent magnet 18 of the rotor directly faces the stator 19 while holding an air gap. (A) is a figure when an air gap is as narrow as L1, (B) is a figure when it expands to L2. On the other hand, FIGS. 11C and 11D show the case of the concave-convex gap type axial gap motor, FIG. 11C shows the case where the air gap is as narrow as L1, and FIG. 11D shows the case where the air gap is enlarged to L2. FIG. Referring to FIG. 12, even if the air gap is the same L1, the uneven gap type is inversely proportional to the square of the gap distance L when the air gap L is increased by about twice the torque of the plain gap type. Although the torque decreases, the concave and convex gap type always has the stator and the first teeth of the rotor facing each other in the radial direction until the gap L is L2, so the torque is almost linear as shown in the figure. Decrease. The linear decrease means that the torque can be linearly controlled by the variable control of the gap L, and when used as an EV motor, the vehicle can be easily controlled from low speed to high speed. Furthermore, as the result of the trial production, it was found that although the motor of the present invention is an axial gap type motor, there is a radial gap type facing portion, so the noise is significantly larger than that of a plain gap type axial motor. There is also a low merit.

  FIG. 13 is a diagram for explaining the characteristics when the air gap of the BLDCM axial variable gap motor is varied. The speed-load torque characteristic when the air gap is minimum is a solid line (1), and the current-load torque characteristic at that time is a dotted line (2). When starting with the starting torque T1 and speed N1 in the speed-load torque curve of the solid line (1) with the minimum air gap, the current I1 is close to the maximum current, and the axial suction force increases and is set larger than the preload spring force. If so, the motor speed increases after starting with a large torque while maintaining the minimum air gap. As the speed increases, the load torque decreases and the load current also decreases. As a result, the axial suction force also decreases, so that the air gap becomes larger in the spring preload, and the air gap increases. The speed-load torque characteristic at the time of the maximum air gap where the gap length has increased to a predetermined air gap is a solid line (3), and the current-load torque characteristic at that time is a dotted line (4). At that time, the load torque is T2, and the current is I2. That is, the speed-load torque characteristic of the motor of the present invention continuously changes steplessly from the solid line (1) to the solid line (3) to start and accelerate the load. If the speed-load torque characteristic is fixed to the air gap and only the solid line (1), the speed increases only to N2 at the load torque T2, but the speed-load torque characteristic (3) is increased with the variable air gap motor of the present invention. The speed can be increased up to N3 above. If this is set to (1) for the strong field and (3) for the weak field control, an extra exciting coil, field control power, or a complicated vector control circuit is required.

  In the above description, the axial gap type BLDCM is mainly described in the case where the opposing surfaces of the stator and the rotor are engaged with each other. Further, even in an SRM that does not use a permanent magnet, sufficient effects can be obtained if the opposing surfaces of the stator and the rotor are made to be opposed to irregularities, arcs, or triangular teeth. In the case of SRM, the speed-torque curve shown in FIG. 13 is not as clean as BLDCM, but if the air gap is increased, the characteristic curve changes with a tendency from (1) to (3). Therefore, the development of the SRM of the present invention is beneficial because it can be performed with an inexpensive motor that does not require a permanent magnet.

  The axial gap type rotating electrical machine according to the present invention is simple and extremely practical, inexpensive, robust, light and thin, suitable for high torque, high efficiency, and low noise. Therefore, it is expected to make a significant industrial contribution.

1, 19, 24 Stator core 2 Winding wire 3, 9 Spacer 4 Rotor magnetic pole 5, 18 Permanent magnet 6, 17, 25 Back yoke or rotor support,
7 Fixed position rotating pulley 8 Variable position pulley 10 Sliding bearing 11 Bearing 12, 26, 27 Plate 13 Weight 14 Elastic member 15 V-shaped belt 16, 23 Coil spring 20 Secondary side tacking rotating shaft 21 Secondary pulley 22 Spring stopper 28 Rotating body 30 Cavity cone 50 Axis

Claims (8)

A stator,
A rotor arranged to be rotatable with respect to the stator through an air gap in a rotation axis direction;
In a rotating electrical machine having a primary side mechanism that rotates coaxially with the axis of the rotor,
The primary side mechanism includes a fixed-position rotating pulley disposed so as not to move in the rotation axis direction, and a variable-position pulley disposed so as to be movable along the rotation axis direction with respect to the fixed-position rotating pulley. ,
The rotating electric machine is characterized in that the variable position pulley rotates integrally with the rotor and moves in the axial direction. In the rotating electrical machine according to claim 1,
The variable position pulley has a conical internal space between the rotor and the rotor, and a plate having an inclined surface in a direction opposite to the internal direction of the conical body provided in an axially immovable manner in the space. A weight divided into one or more in the circumferential direction of the rotating shaft in a space formed by
The rotating electric machine according to claim 1, wherein the weights are assembled in series by an elastic member that urges in the direction of diameter reduction if necessary. In the rotating electrical machine according to claim 1 or 2,
The rotating electric machine includes a permanent magnet magnetized with an even number of poles and different polarities in the circumferential direction. In the rotating electrical machine according to claim 1 or 2,
The rotary electric machine is characterized in that the rotor does not include a permanent magnet. In the rotary electric machine according to any one of claims 1 to 4,
The stator has a plurality of winding salient cores that are concentric arcs and protrude in the axial direction with a first tooth portion, and the winding shaft is formed in parallel with the rotating shaft. It has a stator core with multiple salient pole cores distributed in the circumferential direction.
The rotor is arranged so that the rotor magnetic poles of a plurality of magnetic bodies are distributed in the circumferential direction, and each rotor magnetic pole is concentric and axially meshed with the first tooth portion via the air gap. A rotating electrical machine characterized by having a protruding second tooth portion. The rotating electrical machine according to any one of claims 1 to 5,
A rotating electrical machine characterized in that a variable-width V-groove is formed by fixed position and variable position pulleys of the primary side mechanism and the secondary side mechanism and a V-shaped belt is bridged to constitute a continuously variable transmission mechanism. In the rotating electrical machine according to claim 6,
A rotating electrical machine characterized in that electric power is input to one of the stator or the rotor having a winding to rotate the primary side mechanism machine to obtain an output from the secondary side mechanism. In the rotating electrical machine according to claim 6,
A rotating electrical machine, wherein a driving force is input to the secondary side mechanism by an external force such as wind power, hydraulic power, or an engine, and the rotating electrical machine provided in the primary side mechanism is used as a generator.

Images